Kahn, Outworld Ruler

+1: Place a charge counter on target creature an opponent controls with, "When this creature dies you gain +1 Loyalty".
-3: Destroy target creature. If 3 of your opponents creatures with charge counters on them are destroyed you win the game.
-X: Transform Loyalty into toughness then block target attacking creature. Blocked creature becomes exiled and you regain half the Loyalty lost.